Development and validation of a turbidimetry method for hydrogen sulphide evaluation in effluents of phosphoric acid production unit

摘要

The aim of this study was to develop and validate a simple, new and efficient method for the analysis of hydrogen sulphide (H2S) released from the effluents of phosphoric acid production units. H2S sampling was performed by absorption of the industrial gas into a cadmium acetate absorbing solution. The formed cadmium sulphide (CdS), as a result of a chemical reaction, was analysed by turbidimetry. A methodical validation study of the proposed method was performed according to the requirements of ISO 17025 standards. The proposed method was demonstrated to be precise, linear and accurate over a concentration range of 6.91-92.16 mg/l. Detection and quantification limits were equal to 5.09 mg/l and 6.91 mg/l, respectively. Sample analysis had to be performed within 48 h of the sampling step. The turbidimetry method was applied successfully to the industrial gaseous effluents and can be considered as an economical alternative to the iodometric method.